The incident happened in the Suntsar area of Gwadar district, 1,420 kilometres (882 miles) southwest of Quetta, the capital of the oil and gas rich Baluchistan province that borders Iran and Afghanistan.

He said at least seven coastguard officials were also injured in the early morning attack.

A local tribal police official Muhammad Ali also confirmed the attack and casualties and said the identity of the attackers was not immediately known.

Baluchistan suffers from both Islamist militancy and a regional insurgency which began in 2004, with rebels demanding political autonomy and a greater share of profits from the region's natural resources.

The province has also increasingly become a flashpoint for surging sectarian violence between Pakistan's majority Sunni Muslims and Shiites, who account for around a fifth of the country's 180 million people.